There are a bunch of different layers in the Matched series, including a dystopian plot about a repressive Society and a Twilight-like love triangle. What part do fans get most excited about? They’re passionate about who Cassia ends up with. I get a lot of emails making a case for Ky or for Xander. As a former teacher, I’m like, ”They’re writing a persuasive essay on my book!” They also like to see if Cassia’s going to succeed in overthrowing the Society, which I find fun because she’s a quiet character. She’s not a firebrand. She’s not killing people or anything like that. So I think I like it that they see her as being able to do that even though she’s more of an Everygirl.

How does it feel to bring Cassia, Ky, and Xander’s story to a close? It felt pretty satisfying, just because I’ve been plotting the series for four years. That isn’t forever, but it’s a long time to wait for the characters to finish their journey.

Without spoiling anything, tease for me how readers might be feeling at the end of Reached. I’m hoping they’ll feel satisfied with the end of the series, but I’m anticipating some sorrow. I hope that means that I’ve done my job right. Team Ky and Team Xander are fun, but I wanted readers to root for both. I never wanted it to be either-or. I think that both of them—even though it won’t be easy for some fans — do get what they need.

I know the Matched movie is in development at Disney. Any news? I’m excited about it being with Disney because they were the first to love it. I did talk to the screenwriters, Kieran and Michele Mulroney, the husband-and-wife team that wrote Sherlock Holmes: A Game of Shadows. The parts they were talking about were the parts I cared about most, so that was fun. But I don’t know any more than anybody else at this point.

Any casting wishes? I’m 34, so I’m mostly thinking about whose dad Nathan Fillion could play. [Laughs] A lot of fans have been sending pictures of actors. I just saw Logan Lerman in The Perks of Being a Wallflower. A lot of fans have mentioned him, and I was kind of dying because he’s the cutest thing ever — he would be a great Ky. Also, Nina Dobrev from The Vampire Diaries.

She looks like the girl on the covers. She does. I think she would be lovely. You hope you can get someone wonderful.

Speaking of the covers, readers go crazy for them. They’re not just beautiful, they also track Cassia’s gradual rebellion against the Society. It’s embarrassing, but when the designer [Theresa Evangelista] sent me the final Reached cover, I cried. The progression is really genius.

One of the best parts of writing YA is the fan interaction, right? My favorite thing is getting a letter from a mom or a teacher saying, ”I have this kid and they didn’t like to read until I gave them your book.” I’ve had kids show up to readings in Team Ky or Team Xander shirts. I think that was the moment when my family felt I had arrived.